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Biomedical subjects

Y Yamane

Publications and source records attributed to Y Yamane.

At least 37 records · Page 2Linked to original sources
PubMed2001

Acclimation to the growth temperature and the high-temperature effects on photosystem II and plasma membranes in a mesophilic cyanobacterium, Synechocystis sp. PCC6803.

High-temperature effects on Photosystem II and plasma membranes, temperature dependence of growth, and acclimation to the growth temperature were studied in a mesophilic cyanobacterium, Synechocystis sp. PCC6803. The following results were obtained. (1) Small but distinct temperature acclimation of the PSII reaction center activity was shown for the first time when the activity was measured at inhibitory high temperatures. However, the reaction center activity showed no apparent acclimation when it was measured at growth temperatures after heat stress. (2) Oxygen-evolving activity and the permeability of plasma membranes showed higher resistance to heat when PCC6803 cells were grown at higher temperatures. (3) Acclimation of photosynthesis to the growth temperature seemed to occur so as to maintain photosynthesis activity not at a maximum level but in a certain range at the growth temperatures. (4) Neither sensitivity to high-temperature-induced dissociation of phycobilisomes from the PSII reaction center complexes nor degradation of phycocyanin were altered by changes in the environmental temperature. (5) A close relationship between the viability of cells and the structural changes of plasma membranes (but not the inactivation of photosynthesis) was observed. The denaturation process of PSII complexes and the relationship between the temperature dependence of the growth of Synechocystis PCC6803 cells and that of the photosynthetic activity are also discussed.

Cell Membrane↗
PubMed2001

Nonselective endothelin receptor antagonist initiated soon after the onset of myocardial infarction may deteriorate 24-hour survival.

To investigate the effects of endothelin blockade initiated immediately after the onset of myocardial infarction on survival and left ventricular remodeling, treatment with the nonselective receptor antagonist TAK-044 (n = 22) or saline (n = 19) for 3 weeks was initiated immediately after coronary ligation in rats. The 24-h survival rate was significantly lower in the TAK-044 group than in the saline group. The systolic blood pressure 24 h after the onset of myocardial infarction was similar in the saline and TAK-044 groups, although it was significantly lower in the TAK-044 group during the 3-week protocol. Heart weight/tibial length was significantly increased in the TAK-044 group compared with the saline group. As all deaths in the TAK-044 group occurred within 24 h after myocardial infarction, we performed additional experiments using a separate group of rats 12-16 h after myocardial infarction. Plasma and myocardial endothelin-1 levels were significantly increased, and a bolus injection of TAK-044 significantly reduced left ventricular dP/dtmax in these rats that had had a myocardial infarction compared with sham-operated rats. Endothelin receptor blockade initiated immediately after the onset of myocardial infarction may deteriorate acute-phase survival and left ventricular remodeling. Inhibition of the positive inotropic action of endothlin-1 may partially explain the increased 24-h mortality.

Animals↗
PubMed2001

Partial bladder resection in a bitch with urinary retention following surgical excision of a vaginal leiomyoma.

Ovariohysterectomy and surgical excision of a vaginal leiomyoma were performed in a bitch exhibiting continuous bleeding from the vulva. Following excision of the tumour, urine retention and urinary incontinence developed. Treatment using drugs and an indwelling catheter was unsuccessful in correcting the disorders and chronic cystitis developed after long-standing urine stagnation in the bladder. The authors resorted to undertaking partial cystectomy in order to correct the condition, which resulted in reduced urine retention and improved micturition.

Animals↗
PubMed2001

Plasma digoxin concentration in dogs with mitral regurgitation.

Fifteen and eight mature beagles, without (normal group) and with experimental mitral regurgitation (MR group), respectively, were given 0.02 mg/kg/day digoxin powder for 10 days orally. The optimum time for sample collection after administration of digoxin was observed to be 8-18 hr and 10-22 hr in the normal and MR groups, respectively. In both groups, a stable concentration was reached after 3-5 days of treatment. No differences in plasma level were observed between sexes. The optimum concentration of digoxin was attained at an earlier stage than has been previously reported for both dogs and humans.

Animals↗
PubMed2001

Supplemental embolization coil implantation for closure of patent ductus arteriosus in a beagle dog.

Embolization coil for the occlusion of patent ductus arteriosus (PDA) was inserted in a beagle dog diagnosed as PDA with systolic murmur. Residual shunt was observed three months postoperatively and then supplemental coil was inserted. In the past only one coil was required for the closure of PDA in our cases with good post-operative results. In this case, however, the largest coil presently available (8 mm in diameter with 5 loops) was inadequate to make sufficient closure within 3 months postoperatively and supplemental coil insertion was necessary to produce a successful occlusion.

Animals↗
PubMed2001

Hypertrophic cardiomyopathy in two kittens.

Two 2-month-old kittens presented with a loud cardiac murmur. One cat showed severe signs of heart failure such as respiratory effort and exercise intolerance. Echocardiography revealed left ventricular concentric hypertrophy and severe left ventricular outflow obstruction. They died at 5 and 12 months of age, respectively. Necropsy and histopathology confirmed hypertrophic cardiomyopathy.

Animals↗
PubMed2001

Mast cell MMP-9 production enhanced by bacterial lipopolysaccharide.

Although mast cells contribute to host protective immunity against bacterial infections, the exact mechanism of their recruitment at the affected site has been unclear. Recently, we have reported that both mouse and human mast cells are capable of producing matrix metalloproteinase (MMP)-9, a matrix-degrading enzyme necessary for leukocyte transmigration. Here, we demonstrated that bacterial lipopolysaccharide (LPS) enhanced MMP-9 production of mouse bone marrow derived-cultured mast cells. This action of LPS was partially suppressed by the pretreatment of cultured mast cells with a protein kinase C (PKC) inhibitor, indicating the possible involvement of PKC signaling pathways in the production of MMP-9 by LPS. Thus, these suggest the upregulation of mast cell MMP-9 by bacterial components, thereby resulting in their migration at the affected site.

Animals↗
PubMed2001

Experimental study of materials for patch graft on right ventricular outflow tract under extracorporeal circulation in dogs--comparison between Denacol EX-313-treated bovine jugular vein graft and expanded polytetrafluoroethylene (EPTFE) graft.

A comparison between a bovine jugular vein treated with a hydrophilic polyepoxy compound cross-linker (Denacol), and expanded polytetrafluoroethylene (EPTFE), an artificial material, as a patch graft for the reconstruction of the right ventricular outflow tract under extracorporeal circulation in dogs, as if they had pulmonic stenosis, was made. Hemodynamic and histological examinations were conducted two weeks after the transplantation. Hemodynamic problems were not observed in either the Denacol or EPTFE groups. Macroscopically, organization of new tissue on the graft surface was more marked in the EPTFE group than in the Denacol group, and newly-formed tissue was seen surrounding the border of the graft and burying it in the EPTFE group. In the Denacol group, microscopic findings revealed the presence of inflammatory cells and fibroblasts, and an invasion of the graft by collagen fibers and elastic fibers. In the EPTFE group, there was minimal cellular infiltration of the graft and a thick layer consisting of collagen fibers and fibroblasts was observed around the graft. These results indicated that two weeks after transplantation the graft was better assimilated and organized with blood vasculature in the patch graft in the Denacol group than in the EPTFE group.

Animals↗
PubMed2001

Involvement of the cholinergic pathway in the pathogenesis of pituitary Cushing's syndrome.

Transsphenoidal adenomectomy is currently the first choice for treatment of patients with pituitary ACTH-dependent Cushing's syndrome. However, pharmacotherapy is prescribed for some patients, e.g., unsuccessful surgery. We treated a woman in whom pituitary Cushing's syndrome was improved while she was on antimuscarinic cholinergic agents, atropine sulphate and pirenzepine hydrochloride. The diminished effect of anticholinergics on ACTH and cortisol was incidentally identified in an inferior petrosal sinus sampling procedure. A single intramuscular injection of atropine significantly decreased both ACTH (43.9 pg/ml to less than 12.0; normal, 12.0-40.0 pg/ml) and cortisol (29.9 microg/dl to 13.6; normal, 7.6-23.6 microg/dl). An M1-muscarinic receptor specific antagonist, pirenzepine hydrochloride, also had a diminishing effect on these hormones and this inhibiting effect was partially blocked by the simultaneous administration of an anticholinesterase agent, pyridostigmine bromide. Chronic oral ingestion of these agents led to improvement in clinical symptoms, and urinary 17-hydroxycorticosteroid and 17-ketosteroid levels were at normal to upper-normal levels. This is the first documentation of involvement of the cholinergic system in the pathogenesis of pituitary Cushing's syndrome.

17-Hydroxycorticosteroids↗
PubMed2001

Device for the removal of button batteries.

OBJECTIVE: There is an increasing number of accidents by erroneous ingestion of button batteries in recent years; the batteries arouse the interest of infants because of their attractive shape and luster. The batteries remaining in the gastrointestinal tract and discharging electric current over a long period of time may induce ulceration or perforation, thus must be carefully considered the selection of appropriate treatment. METHODS: We remove erroneously ingested button batteries with two tubes with ferrite magnets nearly the same size as the button batteries themselves. PATIENTS: Four cases of erroneous ingestion of button batteries. RESULTS: We easily removed button batteries from the stomach within 5 minutes in all cases with two magnet-attached tubes. CONCLUSION: We present this battery removal device together with a literature review, because it seems convenient and useful.

Equipment Design↗
PubMed2001

Mechanism of adhesion between 4-META resin and alloys based on Bolger's acid-base interaction.

The water durability at adhesion interfaces between 4-META resin and Au-In or Au-Si alloys was investigated by the peeling test and by surface analysis using X-ray photoelectron spectroscopy (XPS) as well as theoretical consideration based on Bolger's acid-base theory. XPS spectra demonstrated that several-nm thick layers of In2O3 and SiO2 were formed on the Au-In and Au-Si alloys. The water durability of the Au-In alloys increased with increases in In content. The Au-Si alloy and quartz glass specimens showed a total absence of water durability. Bolger's theory suggested that the interaction of 4-MET with In2O3 was considered to be ionic and stable in the presence of water while that of 4-MET with SiO2 was due to hydrogen bonds, which can easily be dissociated in the presence of water. These findings suggest that Bolger's theory is useful for evaluating chemical interactions between an adhesive monomer and oxides on a precious metal alloy.

Acrylic Resins↗
PubMed2001

XPS study on the weakest zone in the adhesion structure between resin containing 4-META and precious metal alloys treated with different surface modification methods.

Three precious metal alloys, Type IV gold alloy, 14 K gold alloy, and silver-based alloy, were treated with different surface modifications including a metal primer (VBATDT) application, a SiOx coating method, high-temperature oxidation, modification method with a liquid Ga-Sn alloy, and tin electroplating. Then thin PMMA films were bonded with a resin containing 4-META. Water durability at the adhesion interface was evaluated after water immersion, followed by thermal cycling used liquid nitrogen. The weakest zone at the interface was investigated using XPS only for the Ag-Pd alloy specimens that had been surface-treated with as-polishing, adhesive primer, and the SiOx coating method, since peeling of the PMMA film on the surface of specimens surface-treated by other methods was not observed. Metal elements were detected from the resin side at the adhesion interface. The chemical states of Cu in the resin before argon ion etching were characterized as metal oxides and/or states of chemical interaction with 4-META, VBATDT, or SiOx.

Acrylic Resins↗
PubMed2001

[A case of adrenal metastasis of lung cancer treated by carboplatin and docetaxel].

A 42-year-old male was referred to our hospital in October 1998, suffering from severe cough accompanied by repeated hemosputa. Serum NSE slightly increased and cytology of sputum indicated class V. Chest X-P and CT revealed a large tumor in the right upper lobe and hilar lymphadenopathy. Abdominal CT revealed bilateral adrenal tumors. For continuous bloody sputum, a right upper lobectomy and lymphadenectomy were performed and the pathologic diagnosis was large cell carcinoma. After surgery, we chose radiation and chemotherapy. The new chemotherapeutic agent docetaxel (60 mg/m2 in combination with carboplatin (CBDCA: AUC 6,800 mg/m2) was administered, resulting in the remarkable reduction in the size of adrenal metastasis by 50% after 3 courses of chemotherapy. Furthermore, 12 months later, the right adrenal metastasis was remarkably reduced (5 x 3 cm-> 0.5 x 1.0 cm), and the left adrenal metastasis had disappeared on abdominal CT. These findings may suggest the efficacy of newly developed docetaxel in cases of non-small cell lung cancer.

Adrenal Gland Neoplasms↗
PubMed2001

[Successful non-invasive positive pressure ventilation therapy to acute respiratory failure after volume reduction surgery for patient with severe emphysema: report of a case].

A 55-year-old man consulted our hospital because of short of breath. Chest CT showed low attenuation areas and we diagnosed his illness as a chronic respiratory failure by chronic lung empysema. He was perfomed bilateral lung volume reduction surgery (VRS), after a few days who was in serious acute respiratory failure. He was treated by non-invasive positive pressure ventilation (NIPPV) for those. After that general condition and arterial blood gas data was improved. NIPPV may be one of the effective tools for acute respiratory failure after VRS.

Acute Disease↗
PubMed2000

Long-term right ventricular volume overload increases myocardial fluorodeoxyglucose uptake in the interventricular septum in patients with atrial septal defect.

BACKGROUND: Several studies have shown that long-term right ventricular (RV) overload in animal models alters myocardial energy substrate metabolism. However, whether long-term RV volume overload alters this metabolism in the human is unclear. METHODS AND RESULTS: We performed positron emission tomography with [(18)F]fluorodeoxyglucose (FDG) and single-photon emission tomography (SPECT) with [(201)Tl]TlCl (Tl) and [(123)I]15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) in 11 patients with atrial septal defect (ASD) and 11 control subjects. In the FDG study, we calculated myocardial metabolic rate of glucose (MMR) in interventricular septum (IVS) and left ventricular (LV) free wall. MMR was significantly increased in IVS compared with LV free wall in the ASD patients (420+/-35 versus 333+/-32 mol x kg(-1) x min(-1); P<0.05) but not in the control group (347+/-27 versus 357+/-25 mol x kg(-1) x min(-1)). In both ASD and control groups, SPECT count was not significantly different between IVS and LV free wall in Tl (ASD, 160+/-11 versus 177+/-12; control, 141+/-12 versus 157+/-14 counts per 15 minutes) and BMIPP studies (ASD, 203+/-14 versus 212+/-18; control, 162+/-16 versus 176+/-16 counts per 15 minutes). MMR in the IVS/LV free wall ratio in the ASD group significantly correlated with indices related to RV volume overload. CONCLUSIONS: Given the assumption that long-term RV volume overload did not affect the lumped constant, the present study suggests that, unlike myocardial perfusion or fatty acid analogue uptake, myocardial glucose utilization in IVS relative to LV free wall is increased in relation to long-term RV volume overload in patients with ASD.

Adult↗
PubMed2000

An intrapulmonary teratoma associated with bronchiectasia containing various kinds of primordium: a case report and review of the literature.

An intrapulmonary teratoma (IPT), multiloculated and bronchiectatic, with two polyps inside a 23-year-old man is reported. The IPT, a very rare benign cystic lesion, was communicating with segmental bronchus and was removed by a segmental resection from the upper lobe of the left lung. The teratoma contained various kinds of primordial derivatives, such as mesoderm, ectoderm, and endoderm. Though 65 cases of IPT have been reported in the literature (1839-1996), in the present case there were over 15 germ derivatives, the largest number reported to date. The tumor contained thymic tissue, apart from mediastinum, which may be significant in relation to the pathogenesis of IPT. Clinical manifestations, age, and gender distributions and the kind of germ cell derivatives are discussed.

Adult↗
PubMed2000

Ischemic hepatitis induced by mesenteric volvulus in a patient with chronic obstructive lung disease.

A 66-year-old man with chronic obstructive lung disease was admitted to our hospital, presenting with mesenteric volvulus and mild liver injury. A superior mesenteric angiogram revealed that the arteries supplying the small intestine were twisted in the arterial phase, while the portal vein was not visualized in the late phase. A celiac angiogram demonstrated that portal blood flow from the splenic venous return was maintained. The patient's symptoms had almost resolved the day after admission, and his serum transaminases level had gradually decreased to normal with conservative therapy. A superior mesenteric angiogram on the 13th hospital day showed a normal arteriogram and the portal vein demonstrated blood flow from the superior mesenteric vein. Liver biopsy revealed hemorrhagic necrosis around the central veins, which was compatible with ischemic hepatitis. Since the patient's O2 saturation level on admission was not low enough to have caused ischemic hepatitis by itself, we suspect that a sudden decrease in portal blood flow was the additional factor that allowed the threshold for the initiation of ischemic liver damage to be reached.

Aged↗